At least 2,000 people in Montenegro demonstrated against membership in NATO days after the small Balkan country was invited to join the security alliance.

The protest outside parliament by as many as 5,000 people December 12 was called by pro-Russian opposition parties which are demanding that a referendum be held on the issue.

Andrija Madic, the leader of the New Serb Democratic Party, told the crowd that if the government does not submit NATO membership to a referendum and tries to pass the decision through parliament, "Montenegro will be brought to the verge of conflict."

The Adriatic country of just over 600,000 is split over NATO because of traditionally close ties to Russia and because NATO bombed the country during the Kosovo war in 1999, while Montenegro was still part of a union with Serbia.

"NATO invited us only to have a few more soldiers against Russia," former president Momir Bulatovic and close ally of late Serbian strongman Slobodan Milosevic, told the crowd. "We should not and must not take part in that game."